Who Discovered DNA?

Are you interested in the history of science, and have you ever wondered who discovered DNA? DNA is short for deoxyribonucleic acid, and it is a nucleic acid that dictates the genetic instructions for all living organisms. It is essentially a blueprint for life and DNA is extremely important. Yet, what was the background to this important scientific discovery? Who discovered DNA?

DNA is a long polymer that is composed of repeating nucleotides. The chain of DNA is about 2.2 to 2.6 nanometres long, and each nucleotide is about 0.33 nanometres long. DNA polymers can be extremely large, and be composed of millions of nucleotides. The largest DNA polymer that is known is about two hundred and twenty million base pairs long.

Who Discovered DNA?

In 1869, the physician Friedrich Miescher first isolated DNA. While examining the substance of pus in surgical bandages, he observed a microscopic substance in the pus. He named it nuclein because he observed it in the nuclei of cells.

Then, in 1919, Phoebus Levene realized that this “nuclein” was composed of a base, a sugar, and a phosphate nucleotide unit. Attempting to discern the structure of the DNA, Levene proposed that it was structured out of a string of nucleotides units that were linked together.

He suggested that they were linked together through the phosphate groups. This conjecture was wrong however, because Levene’s suggested a short chain. He further suggested that the bases repeated in a fixed order, which was incorrect.

DNA Breakthroughs

DNA continued to be studied throughout the years. The next major breakthrough in understanding DNA occurred in 1928. Frederick Griffith realized that the DNA might actually hold genetic information. He realized this when he observed that characteristics of the smooth form of a substance were transferred to the rough form of the same substance, if he mixed a dead form of the smooth substance with a live form of the rough substance.

This was a major discovery into the function and importance of DNA. In 1937, William Astbury contributed to the study of DNA by producing the first X-ray diffraction that exposed that DNA had a regular structure. This was vital in hinting towards a possible structure for DNA.

Then, in 1943, Oswald Avery identified DNA as the transforming principle in the Avery-MacLeod-McCarty experiment. In 1952, Alfred Hershey and Martha Chase performed an experiment which confirmed that DNA had a role in heredity. Their experiment showed that DNA was the genetic material for the T2 phage.

DNA As a Double-Helix

After World War II ended, the race for who could discover the structure of the DNA truly began in earnest. In 1953, James D.Watson and Francis Crick proposed the idea that the DNA’s structure was a double-helix. They made the discovery based on an X-ray diffraction image that was taken by Rosalind Franklin and Raymond Gosling, along with other information concerning how the DNA bases fit together.

They published this idea in the journal, Nature. Five articles subsequently followed this first publication which supported the idea of the Watson and Crick double-helix form for DNA. In 1962, Watson, Crick, and Wilkins received the Nobel Prize for Physiology or Medicine. Rosalind Franklin had died shortly before. Since the Nobel Prize could only be given to living recipients, Franklin could not receive the award.

In 1957, Crick presented the “Central Dogma” of molecular biology. He hypothesized the relationship between DNA, RNA, and proteins. This presentation hypothesized a number of theories which were later proven correct. In 1958, the double-helical form of DNA was proven correct in the Messelson-Stahl experiment.

Thus, the answer to who discovered DNA depends upon the question that you are asking. If you wonder, who first observed and identified DNA? The answer is Friedrich Miescher. However, if you wonder, who first understood what DNA looks like and the structure? The answer is Watson, Crick, Wilkins, and Franklin. Yet, the important thing about DNA is that scientists are still discovering facts about it and learning about it today.